1. Field of the Invention
This invention relates to the structure of hydraulic devices in which energy is transmitted through a liquid coupling from an actuatable drive member to a driven member. More specifically the invention relates to hydraulic impactors in which the drive piston is hydraulically coupled to a driven striker bar and bit through a coupling having a stepped through bore with the end of the bore cooperable with the striking bar being in a fixed ratio with respect to the other end of the bore cooperable with the piston.
2. Description of the Prior Art
Applicants are not aware of any prior art directed to the hereindescribed invention; however, hydraulic impactors to which the invention is applicable are well known. No prior art search was conducted with respect to this invention and the individual inventors did not recall any prior art publications having a relevancy sufficient to warrant an investigation as to whether the inventors' recollections were correct. The individual inventors are aware that various prior art publications exist with respect to impactors and energy transfer through a liquid but not of any publication which is relevant to the instant invention beyond that which is generally known in the field of the invention. Hydraulic impactors with a liquid coupling are shown in U.S. Pat. Nos. 4,166,507, Re 27,244, and 4,062,268; however, these patents as understood do not relate to maintaining a ratio between the areas at the opposite ends of a liquid coupling.